Conventional tumble dryers are commonly used to dry wet clothing. It is also known to provide a clothes drying cabinet for those clothes that are not suitable for conventional dryers. Tumble dryers provide a constant rotation and often heat to dry clothes. This rotation and heat is known to cause damage and shrinkage to clothing dried within the conventional dryer. In particular, a risk of over-drying exists in current dryers, and particularly in those dryers that do not have sensors or other means of detecting dry clothing. Over-drying is caused by excessive or prolonged heat that is applied to clothing and, as a result, over-heats, stresses, damages, and shrinks the clothing fabrics.
Regardless of the form of dryer or method of drying, the basic principles of current drying methods and apparatuses are the same. Current dryers, in theory, attempt to simulate the effects of the sun (i.e., heat), and the wind (i.e., the movement of air and the movement of clothing) for maximum drying efficiency. Typical dryer loads can contain up to a gallon or more of water when the clothes are wet. As a result, a method for removing this water efficiently, safely, and effectively is needed. Therefore, the common conditions used for drying in current conventional dryers and clothes drying cabinets are the addition of heat, the movement of air, and the movement of clothing.
Conventional tumble dryers typically dry clothing at approximately 3.1 lbs. per kilowatt hour. Therefore, the efficiency of such dryers is relatively low, often taking an hour or more to dry a load of laundry even with the addition of heat, expending a significant amount of energy. Moreover, the efficiency of comparable models of conventional tumble clothes dryers is generally the same, with the exception that natural gas dryers are often less expensive than electric dryers to operate, primarily due to the cost of natural gas versus electricity. However, as both gas and electricity are used for heating a dryer, both expel more energy than would otherwise be required by a device that operates simply a fan or blower to circulate ambient air.
Heated air is generally believed to have a greater capacity to absorb moisture than unheated air. Therefore, current methods of drying clothes and dryers are typically directed to the incorporation of heat into the drying cycle to shorten drying times. As a result, conventional methods and devices use termination controls to provide dryer efficiency and energy savings. Termination controls shut the dryer off sooner than it otherwise would have stopped without these controls. Termination controls include simple timers, more advanced temperature sensors, and sophisticated moisture sensors. However, these controls are still prone to problems. Devices with timers and temperature sensors are likely to over-dry clothes because they cannot detect remaining moisture in the clothing. Moisture sensors are less likely to over-dry clothing, but conventional tumble dryers using such sensors do not avoid tumbling action which repeatedly jars and stretches clothing fabrics, and therefore still causes damage to fabrics.
Conventional dryers typically consist of a drum, an idler pulley assembly that assists in rotating the drum, a blower/fan assembly, air seals, a belt, a drive motor, and drum support rollers or bearings. The drive system of each dryer consists of a motor, a pulley and a belt. The drive belt transfers energy from the motor to turn the drum. While not avoiding the problems associated with over-drying and tumble drying, current conventional dryers are also available with a range of temperature and cycle options that allow customization of laundry loads for different types of fabrics and garments. For example, conventional dryers use low heat for delicate fabrics and other fabrics at risk for shrinking. Some conventional dryers include an “air fluff” cycle in which no heat is added to the drying cycle. Other features, such as a cool-down period, or a premature stop, are also used. Unfortunately, as described hereinabove, tumble drying still damages clothing fabrics. Furthermore, most of these methods use heat, which could result in over-drying clothes.
Air movement in a conventional or tumble dryer is created by the motor-driven blower/fan assembly. Room air is drawn into the dryer and over the heater or heating element. The heated air is then circulated in the drum and around the clothing and subsequently exhausted outside. Specifically, air is pulled through the dryer by the motor driven blower assembly. This room air is drawn in over the heating element and heated. Heated air is then introduced to the tumbling clothes in the drum, picking up moisture from the clothes and carrying that moisture out of the drum, often traveling through the lint screen and blower wheel, where it is exhausted to the outside. The tumbling action causes movement of clothing within the drum which is known to expose more surface area of the clothing to the moving, heated air. Therefore, the combination of heat and movement of clothes in conventional methods is believed to shorten drying times. However, aside from the problems of adding heated air which damages fabrics and overall low efficiency of such systems, tumble drying flexes cloth fibers, resulting in damage to the fabric.
Accordingly, as discussed herein, various problems exist for conventional dryers, such as over-drying clothes. Furthermore, drying partial loads of laundry wastes energy because the dryer is not being used in its full capacity. Likewise, filters used to remove lint particles are often filled with lint and must be constantly emptied to keep the dryer operating efficiently. The tumbling of clothes constantly flexes and stretches clothing fabrics, damaging the fabrics. Moreover, often items such as keys, rocks, coins, nails, metal buckles, zippers and buttons or rivets are connected to clothing, or fall out of the pockets of clothing within the dryer. When such items are introduced into a drying cycle of a conventional dryer they damage the drum, scratching and denting the inner surface of the drum as they are tumbled through a drying cycle. Eventually, enough damage is caused to the drum from dents and scratches that the drum, in turn, damages clothing placed in the dryer, such as by snagging or tearing fabric threads.
In an attempt to avoid the problems associated with conventional tumble dryers, clothes drying cabinets have been used. Clothes drying cabinets are typically used to dry clothing that is not suitable for a conventional tumble dryer, such as more delicate items. These clothes drying cabinets often require that the clothes be hung within the cabinet, or laid flat on a surface inside the cabinet. Therefore, they avoid the damage caused by tumbling in conventional dryers.
Current clothes drying cabinets typically include apertures in the cabinet that allow air to permeate into the cabinet, which air causes the evaporation of water from the clothing placed inside the cabinet. To completely dry clothes by evaporation takes a significant amount of time. Therefore, as an alternative, some clothes drying cabinets force air into the cabinet in order to accelerate the drying time of clothes inside the cabinet. However, like conventional tumble dryers, a common feature of many of these forced air clothes drying cabinets is that they add heat to the air to dry the clothes inside. Many of these clothes drying cabinets are, therefore, equally susceptible to over-drying and damaging clothes inside the cabinet. Likewise, these cabinets do not improve upon the efficiency of conventional dryers.
A clothes drying cabinet that uses heated forced air operates similar to a conventional tumble dryer. The primary difference between the two devices is the placement of clothing within the device. While clothes are “tumbled” in a conventional dryer, clothes are typically hung or laid flat within a clothes drying cabinet. Air is drawn into the clothes drying cabinet from the room in which the device is located by a blower/fan assembly, heated, and circulated within the cabinet. Current clothes drying cabinets also provide, similar to a conventional dryer, a duct system or exhaust system to vent air from the interior of the dryer to the exterior environment of a building (“outdoors” or “outside”). Typically, after the heated air is circulated through the cabinet, it is exhausted out of the cabinet, usually through a conventional dryer exhaust duct that is vented outside. Alternatively, it may be possible to recycle air, in which case, air is exhausted from the drying chamber, but is cycled into a condenser, and subsequently cooled. This cooled air may then be either exhausted or reused by reheating and reintroducing the air into the drying chamber. By using heated, and even recycled air, the air is often stale and does not “freshen” the clothes dried within the cabinet.
Some current clothes drying cabinets provide an enclosure for drying and storing clothing that has closeable doors, to provide an aesthetically pleasing appearance to the cabinet, and to conceal the clothing hung inside. These cabinets typically include a rod from which to hang clothes in the interior of the cabinet, as well as a piece of absorptive material, such as a large sponge or a piece of fabric, placed below the clothing. Clothes drying cabinets have also been provided in which the rod is mounted above a drip pan. The drip pan collects excess water that drips from clothing hung on the rod. For those cabinets that use closeable doors, apertures are in some cases provided in the doors to ventilate the cabinet with air.
As discussed previously, cabinets with apertures may avoid the use of heat, and instead allow the circulation of room air into the cabinet to cause the evaporation of water from the clothing placed within the cabinet. As a result, the cabinet avoids over-drying clothing. Additionally, because clothes are hung or rested within the cabinet, the cabinet does not cause the damage tumbling otherwise would cause to clothing in a conventional dryer. However, a cabinet that depends on the natural evaporation of water requires lengthy drying times, particularly when cabinet doors are closed. Closing the cabinet doors restricts the free flow of air into and out of the cabinet. As a result, less air will be available to dry clothes.
Furthermore, the temperature and humidity on a given day will significantly affect the drying time of clothing dried within the cabinet. For example, on a day in which the relative outdoor humidity is high, the air is typically saturated with moisture. As a result, air seeping into the cabinet will be less likely to pick-up and carry away excess moisture from the damp clothing. This leads to a significant increase in the amount of time necessary to dry clothing on a humid day because the air passing over the clothing is picking up less water. Thus, current clothes drying cabinets that depend upon the free flow of air are extremely inefficient.
As an alternative, air could be forced into the cabinet to accelerate the drying time. In some cabinets, gusts of hot dry air are forced into the cabinet from fans or blowers to dry the clothing inside. Like conventional tumble dryers, cool ambient air is drawn from the room in which the device is located into the cabinet, the air is then heated and introduced into the cabinet to dry the clothing hung in the interior of the cabinet. Specifically, ambient air is drawn into the device, heated by a gas or electric heater, and subsequently blown into the cabinet, forcing the hot air across the surface of the wet clothing to cause evaporation. The introduction of heated air, however, risks over-drying and damaging the clothes within the cabinet, and expends a significant amount of energy to heat the clothes.
Clothes drying cabinets typically draw air for use in drying from the room in which the dryer is located, or alternatively recycle air through the device. Further, while current tumble dryers provide an “air fluff” cycle, these tumble dryers do not draw air from the exterior of the building. As a result, the air often used to dry clothes is stale, and may lead to unpleasant odors in the clothes. The use of heat and humidity to de-wrinkle and refreshen clothing hung within the cabinet, likewise, does not provide clothesline freshness to the clothing, as the heat and humidity traps these stale odors within the clothing. Therefore, it would be advantageous to provide a clothes drying cabinet that draws air from the outdoors in order to create the appearance, feel, and smell of clothes that were hung from a clothesline outdoors.
Clothes drying and clothes treating cabinets are also currently available that de-wrinkle clothing by applying heated forced air, moisture, pressure, and tension to the clothing hung within the cabinet. The introduction of steam into the cabinet humidifies the clothing, while a heater and a fan are used to draw air into the cabinet from the exterior of the cabinet, and force the heated air into the cabinet. In addition to the danger of over-drying clothing, a cabinet that additionally applies moisture increases drying times. The addition of pressure and tension stretches, potentially tears, and certainly damages the fabric of clothes placed within the cabinet.
As with conventional dryers, it is also possible, in some clothes drying cabinets to adjust the heat of the air introduced into the cabinet based on the clothing type, such as permanent press, or delicate cycles, as well as adjust the velocity of the blown air, and the drying cycle time to avoid some of the problems of conventional dryers. However, as is the case with conventional dryers, these controls are still likely to damage clothing through over-drying and other problems, and are also inefficient.
In view of the foregoing, therefore, a need exists for a clothes drying cabinet that avoids the damage to clothing caused by over-drying, stretching, and flexing clothing fabrics. A need also exists for a clothes drying cabinet that efficiently dries clothes, while at the same time provides a clothesline fresh appearance, feel, and smell to the dried clothes. A need also exists for a method of drying clothes that draws air from the exterior environment of a building to provide clothesline freshness to clothes hung within a clothes drying cabinet.
The difficulties encountered in the prior art are substantially eliminated by the present invention.